In a flat-panel display (FPD) manufacturing process, a photo-lithography process is in wide used for forming a uniform pattern on a substrate. This photo-lithography process consists of a series of processes which comprise an exposure process, a dry or wet etching process and an ashing process. Generally, the pattern is formed by applying and exposing a photoresist on the substrate, and then carrying out the dry or wet etching process. At this time, a photoresist which is left on a metal wiring is removed using a photoresist stripper.
Until now, a mixture of a primary amines or a secondary amines, and a polar solvent or glycols has mostly used as the photoresist stripping composition for manufacturing LCD. Concretely, Monoethanolamine (MEA) is used as the primary amines, Isopropanolamine (MIPA), etc. has used as the secondary amines, and N-methyllpyrollidone (NMP), Sulfolene or Dmethylsulfoxide (DMSO), etc. is used as the polar solvent. Also Diethyleneglycolmonoethylether (EDG), Diethyleneglycolmonobutylether (BDG), Triethyleneglycolether (TEG), etc. is used as the glycols.
Usually, a photoresist which is left after the etching process is stripped using a stripper and then is washed using water. However, this process brings about a problem wherein impurities are generated because of re-adhesion of the photoresist.
This is the reason that alkanolamine is mixed with water and then hydroxyl ion is generated, thus corrosion to the metal having aluminum considerably increases. Thereby it has needed a special corrosion inhibitor for preventing the corrosion of the metal wiring. However, a prior corrosion inhibitor has the problem that its economic efficiency is low because of its high production cost. Particularly, in manufacturing the Flat-Panel Display like LCD, recently the size of the front surface of the panel has become bigger so that the use of the stripper has increased thereby the rising of the processing cost has been not avoided.
Copper is substituted for aluminum as the material of the metal wiring while the size of the front surface of the panel becomes bigger. However, this brings about the problem that the prior stripper is not applied both to copper and aluminum. In other words, in the TFT-LCD process, until now there is not any photoresist stripper to be able to be all applied to Al process, Cu process, Gate process and COA process.
To solve the problems, the inventors tried to develop all water-borne photoresist stripper by using a tertiary alkanolamine which have not used as the stripper because of its very weak performance of stripping the photoresist. The water-borne photoresist stripper prevents the corrosion of Al and Cu metal wiring, has the good capability of removing the photoresist and may be used to all Al process, Cu process, an organic film process, and COA process.